<?php


namespace encrypt;


class Encipher
{

    private $c = '';
    private $_sourceFile = '';
    private $_targetFile = '';
    private $_writeContent = '';

    //加密的头部注释备注
    private $_comments = array(
        'Author: DaiEr',
        'Email: 2194016116@qq.com'
    );

    private $_key = 'DaiEr';

    public function __construct($sourceFile, $targetFile, $key = '')
    {
        !empty($sourceFile) && $this->_sourceFile = $sourceFile;
        !empty($targetFile) && $this->_targetFile = $targetFile;
        !empty($key) && $this->_key = (array)$key;

        if (empty($this->_sourceFile) || !file_exists($this->_sourceFile)) {
            exit("Source file does not exist.");
        }
        if (empty($this->_targetFile) || !file_exists($this->_targetFile)) {
            //如果源文件不存在，则创建
            fopen($this->_targetFile, "w");
        }
        $this->init();
    }

    private function init()
    {
        $this->q1 = "O00O0O";//base64_decode
        $this->q2 = "O0O000";//$c(原文经过strtr置换后的密文，由 目标字符+替换字符+base64_encode(‘原文内容’)构成)
        $this->q3 = "O0OO00";//strtr
        $this->q4 = "OO0O00";//substr
        $this->q5 = "OO0000";//52
        $this->q6 = "O00OO0";//urldecode解析过的字符串（n1zb/ma5\vt0i28-pxuqy*6%6Crkdg9_ehcswo4+f37j）
    }

    /**
     * 返回随机字符串
     * @return string
     */
    private function createRandKey()
    { // 返回随机字符串
        $str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        return str_shuffle($str);
    }

    /**
     * 写入文件
     * @param $targetFile 写入文件的路径
     * @return $this
     */
    private function write($targetFile)
    {
        $file = fopen($targetFile, 'w');
        fwrite($file, $this->_writeContent) or die('写文件错误');
        fclose($file);
        return $this;
    }

    /**
     * 对明文内容进行加密处理
     * @param $sourceFile  要加密的文件路径
     * @return $this
     */
    private function encodeText($sourceFile)
    {
        //随机密匙1
        $k1 = $this->createRandKey();
        //随机密匙2
        $k2 = $this->createRandKey();
        // 获取源文件内容
        $sourceContent = file_get_contents($sourceFile);

        
        //Aes加密代码内容
        $aes = Aes::encrypt($sourceContent,Aes::getKey($this->_key));
        //混入Aes解密方法函数
        $sourceContent = "eval(\\encrypt\\Aes::decrypt('".$aes."',\\encrypt\\Aes::getKey('$this->_key')));";



        //base64加密
        $base64 = base64_encode($sourceContent);
        //根据密匙替换对应字符。
        $c = strtr($base64, $k1, $k2);
        $this->c = $k1 . $k2 . $c;
        return $this;
    }

    private function encodeTemplate()
    {
        $encodeContent = '$' . $this->q6 . '=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$' . $this->q1 . '=$' . $this->q6 . '{3}.$' . $this->q6 . '{6}.$' . $this->q6 . '{33}.$' . $this->q6 . '{30};$' . $this->q3 . '=$' . $this->q6 . '{33}.$' . $this->q6 . '{10}.$' . $this->q6 . '{24}.$' . $this->q6 . '{10}.$' . $this->q6 . '{24};$' . $this->q4 . '=$' . $this->q3 . '{0}.$' . $this->q6 . '{18}.$' . $this->q6 . '{3}.$' . $this->q3 . '{0}.$' . $this->q3 . '{1}.$' . $this->q6 . '{24};$' . $this->q5 . '=$' . $this->q6 . '{7}.$' . $this->q6 . '{13};$' . $this->q1 . '.=$' . $this->q6 . '{22}.$' . $this->q6 . '{36}.$' . $this->q6 . '{29}.$' . $this->q6 . '{26}.$' . $this->q6 . '{30}.$' . $this->q6 . '{32}.$' . $this->q6 . '{35}.$' . $this->q6 . '{26}.$' . $this->q6 . '{30};eval($' . $this->q1 . '("' . base64_encode('$' . $this->q2 . '="' . $this->c . '";eval(\'?>\'.$' . $this->q1 . '($' . $this->q3 . '($' . $this->q4 . '($' . $this->q2 . ',$' . $this->q5 . '*2),$' . $this->q4 . '($' . $this->q2 . ',$' . $this->q5 . ',$' . $this->q5 . '),$' . $this->q4 . '($' . $this->q2 . ',0,$' . $this->q5 . '))));') . '"));';
        $headers = array_map('trim', array_merge(array('/*'), $this->_comments, array('*/')));
        $this->_writeContent = "<?php" . "\r\n" . implode("\r\n", $headers) . "\r\n" . $encodeContent . "\r\n" . "?>";
        return $this;
    }

    /**
     * 获取解密后内容
     * @param $sourceFileContent 解密前内容
     * @return $this
     */
    private function decodeTemplate($sourceFileContent)
    {
        //以eval为标志 截取为数组，前半部分为密文中的替换掉的函数名，后半部分为密文
        $m = explode('eval',$sourceFileContent);
        //对系统函数的替换部分进行执行，得到系统变量
        $varStr = substr($m[0],strpos($m[0],'$'));
        //执行后，后续就可以使用替换后的系统函数名
        eval($varStr);
        //判断是否有密文
        if(!isset($m[1])){
            return $this;
        }

        //对密文进行截取 {$this->q4}  substr
        $star =  strripos($m[1],'(');
        $end = strpos($m[1],')');
        $str = ${$this->q4}($m[1],$star,$end);
        //对密文解密 {$this->q1}  base64_decode
        $str = ${$this->q1}($str);
        //截取出解密后的  核心密文
        $evallen = strpos($str,'eval');
        $str = substr($str,0,$evallen);
        //执行核心密文 使系统变量被赋予值 $O0O000
        eval($str);
        $this->_writeContent = ${$this->q1}(
            ${$this->q3}(
                ${$this->q4}(
                    ${$this->q2},${$this->q5}*2
                ),
                ${$this->q4}(
                    ${$this->q2},${$this->q5},${$this->q5}
                ),
                ${$this->q4}(
                    ${$this->q2},0,${$this->q5}
                )
            )
        );
        return $this;
    }

    /**
     * 加密函数
     */
    public function encode()
    {
        $this->encodeText($this->_sourceFile)->encodeTemplate()->write($this->_targetFile);
    }

    /**
     * 解密函数
     */
    public function decode()
    {
        $sourceFileContent = file_get_contents($this->_sourceFile);
        $this->decodeTemplate($sourceFileContent)->write($this->_targetFile);
    }
}